A FIELD INVESTIGATION WAS CONDUCTED TO OBTAIN FUNDAMENTAL RELATIONS BETWEEN LOAD AND THICKNESS OF FLEXIBLE PAVEMENT BY STATIC-LOAD TESTING OF FULL-SIZE, SPECIALLY CONSTRUCTED TEST SECTIONS AT HYBLA VALLEY, VIRGINIA. TEST SECTIONS CONSISTED OF THREE-, SIX-, OR NINE-INCH THICKNESS OF BITUMINOUS CONCRETE SURFACE COURSE ON 6-, 12-, 18- OR 24-INCH GRANULAR BASE COURSES CONSTRUCTED ON A UNIFORM CLAY SOIL EMBANKMENT. LOADS WERE APPLIED REPETITIOUSLY THROUGH CIRCULAR STEEL PLATES OF VARIOUS DIAMETERS TO THE SURFACE COURSE, THE BASE COURSE, AND THE SUBGRADE OF EACH OF THE TEST SECTIONS. THE EFFECT OF THE LOADS WAS OBTAINED BY MEASURING BOTH THE DEFLECTION AND THE RECOVERY OF EACH OF THE PAVEMENT STRUCTURE COMPONENTS AND SUBGRADE SIMULTANEOUSLY. THE LOAD- ING TEST DETERMINED THAT OF THE THREE ELEMENTS OF THE PAVE- MENT STRUCTURE, ONLY THE SUBGRADE SOIL OBTAINED A CONDITION OF ESSENTIAL ELASTICITY. ACCELERATED LOAD TEST OBTAINED INFORMATION REGARDING THE GROSS DEFLECTION OF THE PAVEMENT COINCIDENT WITH THE RUPTURE OF THE SURFACE OR THE BREAKDOWN IN ITS RESISTANCE. FOR A GIVEN PAVEMENT SECTION, THE ELASTIC DEFLECTION OF THE PAVEMENT OR OF THE SUBGRADE RESULTING FROM LOADS APPLIED ON THE SURFACE VARIED AS A LINEAR FUNCTION OF THE TOTAL APPLIED LOAD. THE TEMPERATURE OF THE BITUMINOUS SURFACE WAS FOUND TO BE AN IMPORTANT CONSIDERATION IN THE RIGID-PLATE BEARING TESTS OF FLEXIBLE TYPE PAVEMENTS. THE SURCHARGE PROVIDED BY THE BITUMINOUS SURFACE COURSE APPEARED TO HAVE LITTLE EFFECT UPON THE ABILITY OF THE BASE COURSE TO SUPPORT LOAD APPLIED THROUGH RIGID PLATES. THE SURCHARGE PROVIDED BY THE SURFACE PLUS BASE COURSE HAD LITTLE EFFECT ON THE LOAD SUPPORTING CAPACITY OF THE SUBGRADE. A CONSIST- ENT AND ORDERLY INTERRELATION OF THE EFFECT OF UNIT LOAD, DIAMETER OF TEST PLATE, AND PAVEMENT STRUCTURE THICKNESS WAS FOUND. THE UNIT LOAD SUPPORTED BY THE SUBGRADE SOIL AT A GIVEN DEFLECTION DECREASED AT A DIMINISHING RATE WITH AN INCREASE IN SIZE OF LOADED AREA UP TO THAT OF A PLATE 84 INCHES IN DIAMETER, THE MAXIMUM SIZE TESTED. /AUTHOR/